Digital process analysis and control camera system

Abstract

Many continuous processes, such as paper manufacturing, use analog camera systems to capture break events and use the video information to diagnose runnability problems. These systems trigger off a break signal on the machine and synchronize all videos to the same point on the process using the machine speed. The present invention provides a new approach to use real-time information from digital cameras to perform image analysis in real time and execute specific control functions normally performed by operators. A reference image is defined as the control objective function and each frame from the cameras is compared to the reference image. Deviations from the reference image that exceed a defined deadband (the threshold) are output to the control system to take corrective action. The applications of the disclosed approach include dynamic draw control, trim control, tension control, release angle control, creping blade control with control signals determined from a two-dimensional camera image.

1 . A digital vision control system for monitoring and controlling a manufacturing process of a web product occurring on manufacturing equipment comprising: 
 at least one sensor positioned at a pre-determined location adjacent the manufacturing equipment to acquire real time digital images of the web product and the equipment;    a broadband communication network to transfer the real time digital images from the at least one sensor to an analysis system;    said analysis system processing the real time digital images and generating control outputs for communication to the manufacturing equipment by the broadband communication network.    
     
     
         2 . The system of  claim 1  in which the at least one sensor comprises a plurality of sensors positioned at pre-determined locations adjacent the manufacturing equipment.  
     
     
         3 . The system of  claim 1  in which the at least one sensor comprises an analog camera with embedded digital converter.  
     
     
         4 . The system of  claim 1  in which the at least one sensor comprises a digital matrix (CCD) camera.  
     
     
         5 . The system of  claim 1  in which the at least one sensor comprises a digital line scan camera.  
     
     
         6 . The system of  claim 1  in which the broadband communication network is a Gigabit ethernet network.  
     
     
         7 . The system of  claim 1  in which the at least one sensor includes a communication unit to stream digital image data using the Gigabit ethernet protocol.  
     
     
         8 . The system of  claim 1  in which the broadband communication network transfers data using a multicast protocol capable of streaming.  
     
     
         9 . The system of  claim 1  in which the broadband communication network communicates over a medium selected from the group consisting of fiber optic cable, radio frequency, wireless, infrared (IR), and category 5 cable.  
     
     
         10 . The system of  claim 1  in which the analysis system is located remotely from the at least one sensor.  
     
     
         11 . The system of  claim 10  in which the analysis system comprises at least one computer running software algorithms to perform the processing of the real time digital images and generating of control outputs.  
     
     
         12 . The system of  claim 11  in which the at least one computer communicates with the broadband communication network via a switch.  
     
     
         13 . The system of  claim 1  in which the analysis system includes a human machine interface for displaying control and alarm information to an operator.  
     
     
         14 . The system of  claim 13  in which the human machine interface comprises at least one computer with a display for displaying digital images from the at least one sensor as a real time video stream.  
     
     
         15 . The system of  claim 14  in which the computer display displays multiple video streams simultaneously.  
     
     
         16 . The system of  claim 14  in which the real time video stream is generated using decimated images from the at least one sensor to optimize bandwidth.  
     
     
         17 . The system of  claim 16  in which the decimated images are one quarter or one eighth resolution images.  
     
     
         18 . The system of  claim 16  in which decimation of the images is performed at the at least one sensor.  
     
     
         19 . The system of  claim 16  in which decimation of the images is performed by the analysis system.  
     
     
         20 . The system of  claim 14  in which the real time video stream comprises uncompressed images.  
     
     
         21 . The system as claimed in  claim 10  in which the analysis system comprises a processing unit associated with the at least one sensor.  
     
     
         22 . The system of  claim 1  in which the analysis system includes means for remotely setting image acquisition and image stream rates for the at least one sensor, such that the loading of the broadband communication network is dynamically allocatable to any one of the at least one sensor.  
     
     
         23 . A method for monitoring and controlling a manufacturing process of a web product occurring on manufacturing equipment comprising: 
 acquiring real time digital images of the web product and the equipment using at least one sensor positioned at a pre-determined location adjacent the manufacturing equipment;    transferring the real time digital images from the at least one sensor via a broadband communication network to an analysis system;    processing the real time digital images using the analysis system and generating control outputs for communication to the manufacturing equipment by the broadband communication network.